[Study and prevention of contact lens-related microbial keratitis with a standardized questionnaire]

Abstract

Introduction: microbial keratitis is a significant health concern for the one million wearers of contact lenses and their ophthalmologists, with some potentially modifiable risk factors. The number of risk factors for contact lens-related microbial keratitis has been described, but many of them still remain assumed or unknown.

Patients and methods: a multicenter prospective case-control study was conducted in 12 French university hospitals (Besançon, Bordeaux, Dijon, Fort-de-France, Grenoble, Limoges, Lyon, Nancy, Nantes, Paris, Marseille and Strasbourg) beginning in July 2007 on contact lens wearers presenting with microbial keratitis and on healthy contact lens wearers. Patients and healthy wearers were interviewed using a 51-item anonymous standardized questionnaire to determine subject demographics and contact lens wear history.

Results: two hundred and fifty-six patients with microbial keratitis were included. One hundred and thirteen healthy contact lenses wearers were surveyed. Cosmetic contact lens wear highly increased the relative risk (RR) of microbial keratitis (RR, 16.5). Time since the last visit to an ophthalmologist longer than 1 year (RR, 3.4) or prescription by someone other than an ophthalmologist (RR, 7.6) also increased the risk of microbial keratitis. Education on lens care and handling was deficient (hand washing: RR, 2.2; rub and rinse: RR, 2.7).

Discussion: a standardized questionnaire is a powerful tool to determine risk factors for contact lens-related microbial keratitis, but also to analyze individual mistakes in contact lenses use and care.